MANAUS, Brazil — There have been more important games for U.S. Soccer.

The 1989 qualifier in Trinidad and Tobago that put the Americans back in the World Cup for the first time in 40 years, four years before they would host the tournament. The win against tournament favorite Colombia in '94 that gave the U.S. its first World Cup victory since 1950. The group game against star-studded Portugal in 2002 that launched the Americans on their run to the quarterfinals.

None, however, is bigger than Sunday night's game against Portugal.

This is another watershed moment for the U.S. in its emergence as a soccer nation, a chance to fast-forward the development process — on and off the field.

Thanks to Ghana holding Germany to a 2-2 tie, beating Portugal assures the Americans of advancing to the knockout round. That would be three times in the last four World Cups the U.S. has gotten out of the group stage, no small thing for a team still trying to establish itself as one of the world's elite.

And in this delightfully unpredictable World Cup, where chaos reigns and past performance means nothing, anything is possible if the U.S. advances. Jurgen Klinsmann might even have to abandon reality and back off his assertion that the Americans can't win the World Cup.

OK, that's still a stretch. As wildly entertaining as Costa Rica, Chile, Colombia and even Iran have been, it's still early. Wait a week, and odds are the knockout rounds will be filled with familiar names.

Sure, the Americans can beat a Spain or Italy on occasion. Or give full-strength Germany a scare. But it's still considered an upset — at home and abroad — when it happens, and with good reason. They are not strong enough or deep enough for it to happen on a regular basis. Or for them to follow one big win with another and another and still another, as they would have to do to win a World Cup.

With every elite team the U.S. beats, however, they come a little closer. Confidence is a powerful thing that feeds on itself, and the first step in being a powerhouse is believing you deserve to be one.

It goes beyond that, though.

When it comes to soccer, the U.S. is still in its infancy. Sure, it has produced plenty of outstanding players — more every year — and there are Americans holding their own in leagues all over Europe. Major League Soccer has gotten better, too, and is now on par with the second-tier European leagues, like those in Belgium, Norway and even the Netherlands.

But there's a reason Klinsmann has looked to dual nationals to bolster his roster.

With soccer the only game for kids in Europe and South America, they're playing at a world-class level by the time they're teenagers. American kids, on the other hand, split their time and talents between soccer and baseball and basketball — sometimes all in the same day. Of course they're going to trail when it comes to development.

Give those young Americans some inspiration, though, and the U.S. could be creating a monster.

The current U.S. roster is filled with players who got hooked on soccer during the 1994 and 2002 World Cups, and that was without the exposure and interest there is today. Captivate the Nickelodeon set now, and the Americans will reap the benefit in the next 10 to 15 years.

"I woke up today this morning and looked on Instagram and Twitter and saw the posts and videos of people reacting at bars, pubs and out in Chicago at the (fan) event they had there," Alejandro Bedoya said after the Ghana win. "It's awesome that we're part of this movement of growing soccer in the States.

"So it's really cool, and I'm sure everybody feeds off this energy and it's really good to see."

Soccer can no longer be considered a niche sport in the United States. The U.S. bought more tickets for the World Cup than any country besides the host, with FIFA estimating there are 200,000 Americans here in Brazil. Back home, ESPN is doing wall-to-wall coverage of the World Cup — and getting record ratings in return.

And this week, there were more Google searches for soccer than for the NFL. Yes, it's the NFL's offseason. But it is the behemoth of U.S. sports, with every other sport fighting for a share of its spotlight. The longer the U.S. can keep soccer front and center, the better it is for the game.

Losing to or tying Portugal won't set soccer back in the United States. It's come too far. But it still has a ways to go, and a win would give the Americans a shortcut.